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< Change Proposal Index

Links - CLOSED

  • Owner: Nigel Megitt.
  • Started: 27/03/14
  • Closed: 20/01/15

Issues Addressed

Summary and Change details

TTML 1.0 did not define a mechanism for linking to external content.

links and embedded external content

Use cases

  • A user traverses a link to display related content in a different rendering context (frame etc)
  • A user performs an action related to the timed content ("vote for this candidate")
  • A user selects alternate content in the same rendering context, e.g. selecting a different language from a menu
  • An external image should be used to render the contained content in place of the text
  • An external audio clip should be played simultaneously with the contained content

TTML2 Syntax

The <a> element with href and target attributes is permitted.

The attribute actuate may be used to define whether the link should be followed automatically, if it has the value "onLoad" or on manual request, if it has the value "onRequest". The initial value for this attribute is onRequest.

This can appear at any level and contain the children that its parents are permitted to contain.

This element may not contain any styling attributes.

Nested <a> elements would not be permitted.

Example 1 Link

<a href="" target="below_frame">
Press your button now to view more information about this section, below.

Example 2 Embedded content

<p id="p241">
<a href="" target="_self" actuate="onLoad">
This text will be replaced by the referenced image.

Dependencies on other packages


Edits to be applied


Edits applied

Added xlink:* attributes to span and image element types in [2].


May be a different way to include embedded images than has been used in prior implementations.


TBD - combination of HTML <a> and xlink attributes, though not using xlink namespace.